echo 7/udp # July Edition

Thomas Ptacek | July 29th, 2006 | Filed Under: Navel Gazing, Uncategorized

Our readers are cooler than we are, and you can’t see them if you’re just reading us in RSS. Choice comments from July:

Halvar Flake on “Dramatic Speedup in AES Timing Attacks”

[…] Throwing overboard a paradigm that we happen to understand pretty well (S-Boxes, their linear and differential characteristics and how to construct them in order to make modelling them as polynomials annoying) because of an implementation issue that we could fix is “emptying the bath with the child” […]

Dennis Cox on “Improving The Great Firewall of China”

[…] It’s equivalant is the “upstanding” people that bragged about them helping the underground railroad while it was happening for politicial/fame means, which caused parts of the underground railroad to fail. It’s selfish - plain and simple. I wonder what happens when some poor freedom loving person in China that has been using these methods and gets caught? […]

Ivan Arce on “Improving The Great Firewall of China”

I think all of this is irrelevant. My impression is that those “poor freedom loving persons in China” are way smarter that the Watson group and all the rest of us. They do not need to be schooled about MITM attacks and IP/TCP tricks. What’s next? Other clever people will tell them how to break hash functions and how to write exploits…

Dan Ingevaldsen on “Improving The Great Firewall of China”

I’m in China right now, and I don’t have anything to say about the great firewall or anything, but I am definitely wondering why every American here is wearing sweatpants. Can you guys do a blog entry about that? Thanks.

Wendy N. on “Arbor Ops on Why You Shouldn’t Use RFPs”

Not only that, but in the public sector, where all contracts and purchases have to be justified, accounted for and audited in excruciating detail, the RFP is absolutely necessary. You have to prove that you had a planned set of requirements, and you have to demonstrate that your process for selecting the right vendor to meet those requirements was above-board, fair, and provided the “best value” to the taxpayers. (Well, that’s the theory, anyway.) Just try explaining to an auditor that you watched a WebEx and picked up some brochures at a trade show in order to spend $100K …

Paul Morville on “Arbor Ops on Why You Shouldn’t Use RFPs”

Yes, nothing cuts through the marketing bullsh*t like a good RFP! Most RFPs are largely an exercise in cntl-c/cntl-v of the same three year-old copy you’d get through other channels. The stack of paper is undoubtably impressive to auditors and managers, but there are probably more efficient ways than having 5-10 companies collaborate on a giant position-piece.

Mike Rothman on “Arbor Ops on Why You Shouldn’t Use RFPs”

[…] An RFP is one of quite a few information gathering steps that a user can take. Depending on the nature of the purchase, it may make sense or not. But in no way shape or form am I saying RFPs don’t need to happen.

wrc on “Really, MD5 Sucks For Password Storage.”

If you’re talking the good-old-fashioned, traditional crypt(), the speed disadvantage of using md5 disappear once that ninth password character gets used. To defend against a brute force attack, you can increase the search space or increase the time for each search. Both work. Every implementation of md5 for passwords I’ve seen had the capability (if not the actuality) to increase the search space.

Steven on “Really, MD5 Sucks For Password Storage.”

Poul-Henning Kamp’s MD5-crypt, the one used on FreeBSD, is not a single iteration of MD5 over the salt and password. It uses a 1000 iteration loop that continually remixes the password and intermediate hash values. It’s quite a bit slower than crypt(3).

I owe PHK an apology

Greg Hoglund on “My Sacrosanct Kernel”

Trust isn’t based on the technology used. You trust your own code don’t you? After all, you did write it? Or, someone you trusted wrote it? There is some inherent trust in, say, Symantec, when you install their software, right? Do you really believe that using similar technology implies similar intent of the user? You probably are for gun control too? […]

Richard Bejtlich on “Bejtlich Considered Wrong (For A Change)”

External intruder (”outsider”) scenario:

1. Outsider attacks and compromises victim.
2. Victim recovers, outsider remains at large.
3. Return to step 1, except add to the number of outsiders.

Internal intruder (”insider”) scenario:

1. Insider attacks and compromises victim.
2. Victim recovers, and removes insider.
3. The insider population has decreased. Until a new malicious insider is hired, the threat has actually decreased — as opposed to the external intruder scenario.

Josh Daymont on “Symantec Paper Validates Trustworthy Computing?”

Ivan is probably right in regards to this being a bad sign for the new Vista ip stack. I reskimmed the paper and didn’t find the issue of techniques specifically addressed, but most of the language around discovered vulnerabilities indicates that this research did not include any binary analysis of the stack, but instead was limited to testing it through simlpy remotely pentesting the box. If this is the case and then there will definitely be lots of interesting problems lurking behind the scenses, and if microsoft doesn’t have some qualified vulnerability researchers do a binary or code based analysis of the stack before release, well then you can bet your bottom dollar the intruder community will find some 0day when they do just such a thing post release.

Nate Lawson on “Oh, The Bad Crypto You’ll See (an open letter)”

there are only 2 categories of manufacturers.

You’re Not Special (98%): Separate your marketing department’s claims about your product’s external view from the internal design. Nearly all problems boil down to ones already solved by existing protocols and libraries. Encrypting a file? GPG. Sending anything over the wire? TLS/SSL. Your special sauce is in how you glue all these things together to make some product. Don’t reimplement these, and still get review of how you’ve glued them together.

You Are Special (2%):

You are Voltage and you were founded by Dan Boneh. Or your business is cryptanalyzing products in concert with Adi Shamir. Note the most important part here — if you’re special, you are willing to plunk down $400/hour for a full-time cryptographer for at least 6 months.

Chris Wysopal on “Do We Need an ISO Secure Coding Standard?”

The solution is not more lists of things not to do, its checking technology to tell you when you did do one of those things. […]